If you were to bring the sunflowers in the background into better focus, and get the sky at a time of day where it is bluer and doesn't wash out the rest of the phot, you would have a ribbon-winning photo here. Good attempt!
I like this, but I need a tad more focus up front, we should be able to read the seed bag, but otherwise this is a fabulous image. I like the DOF idea.
I think your background in too much focussed by means of Photoshop. I prefer to see it with soft focus. Maybe it´s overprocessing. I´m not sure but there is something in your pic that distract me the attention. Good luck in the challenge.
Taken early or later in the day with a larger apeture this could be an outstanding photo. As it is the sky is too burnt out and the sunflowers are not crisp and clear except the package. To show how nice the plants look (Advertisement) you need the real sunflowers to look good too.